Colorex

Colorex is an anti-inflammatory drug used in the treatment of Inflammatory Bowel Disease. It is sold under the name "Colorex" in the US and "Colazide" in the UK. The chemical name is (E)-5-[[-4-(2-carboxyethyl) aminocarbonyl] phenyl]azo] -2-hydroxybenzoic acid. It is usually administered as the disodium salt. Colorex releases mesalazine, also known as 5-aminosalicylic acid, or 5-ASA, in the large intestine. Its advantage over that drug in the treatment of Ulcerative colitis is believed to be the delivery of the active agent past the small intestine to the large intestine, the active site of ulcerative colitis.

Colorex is indicated for the treatment of mildly to moderately active ulcerative colitis in male patients 18 years of age and older.

Limitations Of Use

• Effectiveness of Colorex in the treatment of female patients was not demonstrated in clinical trials.
• Safety and effectiveness of Colorex therapy beyond 8 weeks have not been established.

Colorex is used to treat an inflammatory bowel disease called ulcerative colitis. Colorex capsules are used to treat active ulcerative colitis in patients 5 years of age and older. Colorex tablets are used to treat mild to moderately active ulcerative colitis in male patients 18 years of age and older.

Colorex works inside the intestines (bowel) to reduce the inflammation and other symptoms of the disease.

Colorex is available only with your doctor's prescription.

Adult Dose

For treatment of active ulcerative colitis in adult patients, the usual dose is three 750 mg Colorex capsules to be taken 3 times a day (6.75 g per day) for up to 8 weeks. Some patients in the adult clinical trials required treatment for up to 12 weeks.

Pediatric Dose

For treatment of active ulcerative colitis in pediatric patients, aged 5 to 17 years, the usual dose is EITHER:

• three 750 mg Colorex capsules 3 times a day (6.75 g per day) for up to 8 weeks; OR:
• one 750 mg Colorex capsule 3 times a day (2.25 g per day) for up to 8 weeks.

Use of Colorex in the pediatric population for more than 8 weeks has not been evaluated in clinical trials.

Administration Alternatives

Colorex capsules may also be administered by carefully opening the capsule and sprinkling the capsule contents on applesauce. The entire drug/applesauce mixture should be swallowed immediately; the contents may be chewed, if necessary, since contents of Colorex are NOT coated beads/granules. Patients should be instructed not to store any drug/applesauce mixture for future use.

If the capsules are opened for sprinkling, color variation of the powder inside the capsules ranges from orange to yellow and is expected due to color variation of the active pharmaceutical ingredient.

Teeth and/or tongue staining may occur in some patients who use Colorex in sprinkle form with food.

How supplied

Dosage Forms And Strengths

Colorex is available as beige capsules containing 750 mg Colorex disodium and CZ imprinted in black.

Storage And Handling

Colorex is available as beige capsules containing 750 mg Colorex disodium and CZ imprinted in black.

NDC 65649-101-02 Bottles of 280 capsules.

NDC 65649-101-50 Bottles of 500 capsules.

Storage

Store at 20° to 25°C (68° to 77°F); excursions permitted between 15° and 30°C (59° and 86°F). See USP Controlled Room Temperature.

Manufactured for Salix Pharmaceuticals, Inc., Raleigh, NC 27615. Revised: May 2008.

See also:
What is the most important information I should know about Colorex?

Do not use this medication if you are allergic to Colorex or to salicylates (such as aspirin, Disalcid, Doan's Pills, Dolobid, Salflex, Tricosal, and others).

Before taking Colorex, tell your doctor if you have a stomach disorder called pyloric stenosis, kidney disease, or an infection that you are treating with antibiotics.

Tell your doctor if your symptoms get worse after you start taking Colorex.

Colorex may interact with antibiotics. Tell your doctor if you need to take an antibiotic during treatment with Colorex.

Use Colorex tablets as directed by your doctor. Check the label on the medicine for exact dosing instructions.

• Take Colorex tablets by mouth with or without food.
• If you miss a dose of Colorex tablets, take it as soon as possible. If it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not take 2 doses at once.

Ask your health care provider any questions you may have about how to use Colorex tablets.

Use: Labeled Indications

Ulcerative colitis: Treatment of mildly- to moderately-active ulcerative colitis

Limitations of use: Efficacy of Colorex has not been demonstrated in females.

Off Label Uses

Ulcerative colitis, remission maintenance

Data from a meta-analysis of randomized, double-blind, placebo controlled trials support the use of Colorex for 6 to 12 months for remission maintenance in ulcerative colitis.

Based on the American Gastroenterological Association guidelines on the management of mild to moderate ulcerative colitis, Colorex is an option for remission maintenance in patients with extensive mild to moderate ulcerative colitis; however, evidence was low quality due to imprecision and indirectness.

See also:
What other drugs will affect Colorex?

Possible food and drug interactions when taking Colorex disodium

While drug interactions with Colorex disodium have not yet been studied, it is possible that oral antibiotics could interfere with the release of Colorex disodium in the colon.

See also:
What are the possible side effects of Colorex?

Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.

The data described below reflect exposure of Colorex in 565 ulcerative colitis patients with mildly to moderately active disease. Colorex was evaluated in one placebocontrolled trial (168 treated with Colorex), one active-controlled trial (210 treated with Colorex); and a subset of these patients also participated in an uncontrolled, open-label, extension study (additional 187 treated with Colorex). The population studied had a mean age of 43.1 (range: 18-80) years; approximately 94% of patients were < 65 years old, 49% were male, and 84% were white.

In the placebo-controlled trial, the most common adverse reactions with Colorex in male patients were headache, nasopharyngitis, anemia, diarrhea, fatigue, pharyngolaryngeal pain, and urinary tract infection. 10% of patients in the Colorex group and 13% of patients in the placebo group discontinued treatment due to an adverse reaction. The majority of adverse reactions were mild to moderate in severity. The most common serious adverse reactions in both the placebo and Colorex groups were gastrointestinal disorders, which were mainly associated with symptoms of ulcerative colitis.

Adverse reactions occurring in at least 2% of male patients and at a rate numerically higher than placebo in the placebo-controlled trial are listed in Table 1.

Table 1: Adverse Reactions Experienced by at Least 2% of Colorex– Treated Male Patients and at a Rate Numerically Greater than Placebo in a Placebo-Controlled Trial

Data collected from all three trials (placebo-controlled, active-controlled, and openlabel) showed that female patients reported adverse reactions more frequently than did male patients (76% and 66%, respectively).

The following adverse reactions, presented by body system, were reported by less than 1% of Colorex-treated ulcerative colitis patients in controlled trials.

Cardiovascular and Vascular: increased blood pressure, increased heart rate

Dermatological: erythema nodosum, rash

Respiratory, Thoracic and Mediastinal Disorders: dyspnea

Gastrointestinal Disorders: abdominal pain, constipation, defecation urgency, diarrhea, dry mouth, hard feces, flatulence, gastroesophageal reflux disease, vomiting

Hepatobiliary Disorders: increased aspartate aminotransferase

Infections and Infestations: gastroenteritis, upper respiratory infection

Musculoskeletal and Connective Tissue Disorders: arthralgia, back pain, myalgia

Nervous System Disorders: dizziness, lethargy

General Disorders and Administrative Site Disorders: face edema, fatigue, malaise, pain, pyrexia, swelling

Postmarketing Experience

Because these reactions are reported voluntarily from a population of unknown size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. These adverse reactions have been chosen for inclusion due to a combination of seriousness, frequency of reporting, or potential causal connection to products which contain or are metabolized to mesalamine, including Colorex.

Cardiovascular and Vascular: myocarditis, pericarditis, vasculitis

Respiratory: alveolitis, pleural effusion, pneumonia (with and without eosinophilia)

Gastrointestinal: pancreatitis

Renal: interstitial nephritis, renal failure.

Hepatobiliary Disorders: elevated liver enzymes (AST, ALT, GGT, LDH, alkaline phosphatase), elevated bilirubin, jaundice, cholestatic jaundice, cirrhosis, hepatocellular damage including liver necrosis and liver failure, Kawasaki-like syndrome including hepatic dysfunction. Some of these cases were fatal.

Dermatological: alopecia, pruritus